code: def testRegression(self):
      self.assertAlmostEqual(
          FlatnessSFX()(list(numpy.linspace(0.0, 1.0, 100))),
          4.7500004768371582,
          1e-6,
      )
  
file_path: essentia/test/src/unittests/sfx/test_flatnesssfx.py
imports: from essentia_test import *
  import numpy
label_desc: Use image node_id 6 for calling the TestFlatnessSfx obj's underlying member method code with example usage: obj.testRegression() without return types